A foreign site put up snippets of all 13 tracks off of Graduation. The snippet for Stronger included the new drums as tweaked by Timbaland. Also, the song Homecoming was put up for purchase on the UK iTunes, so of course that has leaked out to the public. Full song, no DJ, CDQ.
Kanye West - Graduation Sampler
Kanye West - Homecoming (ft. Chris Martin)
As always, should you put this link on your blog, MySpace, or whatever, credit SexyFront.